Porting blackberry apps to iOS and Android

So there is a fair bit of information out there about porting apps from Android to BB10, but what about the other way around? If I build a Native cascades app using Momentics, is it possible (difficult) to port it to other platforms?

The initial releases of BBM for iOS and Android appeared to be direct ports, at least visually. Although they have diverged now to match up with their respective UI guidelines.

Depends on which framework you're going to use on Android(and if you use native c++ BB or QML Cascades), if you use the Android Qt port it will be a heck of a lot easier, I've ported my Cascades App to Sailfish which uses Qt 5 and QtQuick 2, it wasn't that bad, the odd hickup but I've managed.